Monoazo dyestuffs



Patented Nov. 1, 1938 UNITED'STATES PATENT OFFICE MONOAZO DYESTUFFS Heinrich Morschel, Cologne-Deutz, and Otto Goll, -Leverkusen I. G.-Werk, Germany, assignors to General Aniline Works, Inc., New York, N. Y., a corporation of Delaware No Drawing. App ication July 28, 1936, Serial No. 93,116. In Germany August 16, 1935 z Claims.

The present invention relates to new water insoluble monoazo dyestuffs, more particularly it relates to azo dyestuifs of thegeneral formula:

wherein X stands fora member selected from the Example 1 Into an ice cold solution of 175 gs. of l-amino- 7-hydroxynaphthalene in dilute hydrochloric acid there is stirred the diazo solution produced in the known manner from 138 gs. of 2-nitraniline. At a reaction which is weakly acid to Congo red, formation of the dyestuff is soon complete. The reddish brown monoazo dyestuff 4- (2-nitrobenzene) azo-l-amino- 7 hy-droxynaphthalene, which is insoluble in water, is isolated in the usual manner. Affinity for cotton:

The dyestufi corresponds to the following formula:

/H 45 v H Example 2 In a similar manner the monoazo dyestufi from 55 wdiazotized 2-ch1oraniline and l-amino-l-hydroxgrou consisting of hydrogen, .alkyl andaryl, and

ynaphthalene is obtained in a weakly acid solution with a good yield. The dyestufi, which corresponds to the following formula:

dissolves witha reddish brown coloration in an aqueous solution of caustic soda. Affinity for cotton:

Example 3 The monoazo dyestufi manufactured in an acid solution from diazotized 3-nitro-4-anisidine and 1-amino-7-hydroxynaphthalene dissolves with a cobalt blue coloration in concentrated sulfuric acid and with a violet-brown coloration in an aqueous solution of caustic soda. Affinity for cotton: 25%.

The dyestufi corresponds to the following formula:

MGM.

Example 4 Diazotlzed 1-amino-7-hydroxynaphthlene is coupled according to Example 1 with l-amino- 7-hydroxynaphthalene. The monoazo dyestuif, which corresponds to the following formula:

dissolves with a violet-brown coloration in an aqueous solution of caustic soda. Afilnity for cotton: 25%.

Example 5 There is stirred into an ice-cold solution of 182 gs. of l-methylamino-7-hydroxynaphthalene in dilute hydrochloric acid the diazo solution produced in the known manner from 1318 gs. of

2-nitraniline. At a reaction which is weakly acid to Congo red formation of the dyestufi is soon complete. The brownish-red monoazo dye stuff 4- (2-nitrobenzeneazo) l methylamino-7- hydroxynaphthalene which is insoluble in water is isolated in the usual manner.

The dyestufi corresponds to the following formula:

OH: HO

IIIOi Example 6 To a solution of 280 gs. of 1-(4'-methoxyphenylamino)-7-hydroxynaphthalene in 1000 gs. of glacial acetic acid, at 10 0., there is added a 3Qqidiazo solution produced by diazotization of 138 gs. of 4-nitraniline in 500 cos. of glacial acetic acid and 280 cos. of hydrochloric acid of strength with 69 gs. of sodium nitrite. After coupling is complete, the dyestufl 1-(4-methoxyphenylamino) -4- (4 '-m'trobenzeneazo) -7-hydroxynaphthalene is filtered off with suction, washed with acetic acid of 50% strength, and dried. The dyestuff obtained in this manner is a blackish-brown powder, which is soluble in 40 pyridine with a blue coloration.

The dyestuff corresponds to the following formula:

In an analogous manner the following dyestuffs have been produced:

4- (5' -chloro-2-methoxybenzeneazo) -1- methyl amino-7 -hydroxynaphthalene, 4 (2'-chlorobenzeneazo) 1 ethylamino 7 hydroxynaphthalene, 4- (2'-methyl-4'-chlorobenzeneazo) -1-ethylamino-7-hydroxynaphthalene, 4- (2 '-ni tr 0 b enzeneazo) -1-phenylamino-7 -hydroxynaphthalene, 4- (2'-methoxy-benzene-azo) -l-amino-7-hydroxynaphthalene, 4- (2'-methyl-5-chloro-b enzeneazo)-1-amino-7-hydroxynaphthalone, 4-(2-' 'methoxy-5-chloro-benzene-az o) -l-amino-7-hydroxynaphthalene, 4'- (2'-nitro-4-methyl benzeneazo) 1-amino-7 -hydroxynaphthalene, 4- (3 chloro-benzene-azo) -l-ethylamino-7-hydroxynaphthalene, 4- (2'-nitrobenzene-azo) -l-ethylamino-'I-hydroxynaphthalene.

We claim: r 1. Water insoluble monoazo dyestuffs of th 1 general formula:

l N=NR having affinity for the vegetable fiber.

HEINRICH MORSCI- I EL.

OTTO GOLL. 

